Abstract Introduction The diagnosis of apical hypertrophic cardiomyopathy (ApHCM) is contingent on demonstrating maximum wall thickness (MWT) ≥15mm; the same threshold as other HCM subtypes. However, myocardium naturally tapers towards apex in healthy individuals, so ≥15mm MWT proportionately higher than thicker basal segments. Using cardiac magnetic resonance (CMR), relative ApHCM has been des...